The present invention concerns a machine tool for performance of operations on the surface of a part, in particular of large dimensions, for example the production of drillings on an aircraft fuselage element.
More generally, the invention concerns the field of machine tools used to perform automated or semi-automated operations, typically machining or assembly operations, on parts or structures of large dimensions.
Aircraft fuselages or other aeronautical structures such as wings are manufactured in the known manner by the assembly of rigid, generally metal panels onto a structure. To achieve this, the flat or curved panels are positioned on the structure and joined thereto by riveting, for example. This requires the ability to machine the assembly once the panels are in position, typically in order to produce the drillings necessary for riveting.
These operations may be performed by an operator. The development of large dimension robots able to produce drillings on the complete fuselage is onerous.
In order to perform these drillings or other simple machining operations on large dimension assemblies, rapidly and with precision, devices have nonetheless been developed in order to automate these operations in part.
For example, document EP1761360 presents a machine tool comprising two parallel flexible rails fixed to the structure to be machined. The rails are fixed to the structure using suckers. A machining means, typically a drill, moves between the two rails along a transverse module.
Such a device is however complex to implement in that it comprises two rails which must be perfectly parallel. Also, by construction, the width between the two rails and the surface area which can be reached by the machining tool are limited. Finally, such a device is not suitable for a surface with a significant double curvature because of the difficulty of positioning two rails in parallel on such a surface. A pronounced double curvature exists in certain zones of aeronautical structures, in particular certain fuselages.